1. Field of the Invention
The present invention relates generally to tamper-proof caps for containers, bottles and the like, and more particularly, to a tamper-proof cap having a visual indicator that change from a first characteristic to a second characteristic to indicate that the cap has been tampered with.
2. Description of the Prior Art
Tamper-proof closure devices or caps are well known for restricting unauthorized access to the contents of a bottle, container or other enclosure. A typical arrangement consists of a cap or closure which has a portion that is ruptured or "torn away" when the cap is unscrewed and opened for the first time. That fact that a portion of the seal originally formed by the cap has been removed indicates that the container with which the cap is used has been opened thus warning users that the contents might have been compromised. Examples of such tamper-proof or more correctly, "tamper-indicating" cap arrangements are disclosed in the following U.S. Pat. Nos. 4,561,553; 4,638,917; 4,768,666; and 4,899,897.
Another form of well known cap enclosure has means making it difficult to open so that access is limited, especially to small children. Such safety arrangements, referred to herein as "access-limiting" caps, typically require the user to "push down" before the cap enclosure may be unscrewed and removed from the container. This latter form of enclosure cap however, normally does not feature a removable or tearable portion, and thus, does not have means for indicating that the contents of the container might have been tampered with or otherwise compromised.
It is apparent from the foregoing discussion that a clear need exits for an access-limiting cap or closure for bottles, containers, or the like which additionally includes means to indicate that the cap has been opened prior to use of the contents thereof. This requirement for a cap that is both "access-limiting" and "tamper-indicative" is met by the present invention as will be made evident from the following description thereof. Other advantages of the present invention over the prior art also will be rendered apparent.